title: Biochemical parameters of Saccharopolyspora erythraea during feeding ammonium sulphate in erythromycin biosynthesis phase.
abstract: The physiology of feeding ammonium sulphate in erythromycin biosynthesis phase of Saccharopolyspora erythraea on the regulation of erythromycin A (Er-A) biosynthesis was investigated in 50 L fermenter. At an optimal feeding ammonium sulphate rate of 0.03 g/L per h, the maximal Er-A production was 8281 U/mL at 174 h of growth, which was increased by 26.3% in comparison with the control (6557 U/mL at 173 h). Changes in cell metabolic response of actinomycete were observed, i.e. there was a drastic increase in the level of carbon dioxide evolution rate and oxygen consumption. Assays of the key enzyme activities and organic acids of S. erythraea and amino acids in culture broth revealed that cell metabolism was enhanced by ammonium assimilation, which might depend on the glutamate transamination pathway. The enhancement of cell metabolism induced an increase of the pool of TCA cycle and the metabolic flux of erythromycin biosynthesis. In general, ammonium assimilation in the erythromycin biosynthesis phase of S. erythraea exerted a significant impact on the carbon metabolism and formation of precursors of the process for dramatic regulation of secondary metabolites biosynthesis.
authors.affiliation: East China University of Science and Technology, Shanghai 200237, China.
authors.forename: X
authors.initials: X
authors.lastname: Zou
authors.forename: W-J
authors.initials: WJ
authors.lastname: Li
authors.forename: W
authors.initials: W
authors.lastname: Zeng
authors.forename: H-F
authors.initials: HF
authors.lastname: Hang
authors.forename: J
authors.initials: J
authors.lastname: Chu
authors.forename: Y P
authors.initials: YP
authors.lastname: Zhuang
authors.forename: S L
authors.initials: SL
authors.lastname: Zhang
mesh_terms: D000586:Amination / Q000187:drug effects; D000596:Amino Acids / Q000378:metabolism; D000645:Ammonium Sulfate / Q000378:metabolism* / Q000494:pharmacology; D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism; D002952:Citric Acid Cycle / Q000187:drug effects; D004917:Erythromycin / Q000096:biosynthesis*; D005285:Fermentation / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D016930:Saccharopolyspora / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D002245:Carbon Dioxide; D018698:Glutamic Acid; D004917:Erythromycin; D010100:Oxygen; D000645:Ammonium Sulfate